This codebase is following the Procedural Programming approach. In Procedural Programming, functions are often declared at the beginning of the code, and their actual implementations are provided later in the code. This approach promotes a step-by-step, imperative style of programming.

The % operator, also known as the modulus operator, is used in C++ to determine the remainder of the division of one integer by another. For example, 5 % 2 equals 1 because 2 divides into 5 twice with a remainder of 1.

If none of the conditions in an if-else if structure are met, and there is no else clause, the program simply continues execution without executing any of the code blocks in the if-else if structure. This behavior is often desired when you have a series of conditions and you don't want any specific action when none of them is met.

The use of the "goto" statement in C++ is generally discouraged because it can lead to spaghetti code, making the code harder to read and maintain. It creates unstructured jumps in the code, making it challenging to follow the program's flow. Therefore, it often degrades both readability and maintainability.

In C++, when both declaration and definition of a function are available but with different default argument values, the compiler selects the default values from the definition. This ensures consistency in behavior when the function is called from different parts of the code, as the definition takes precedence.

John should use an If-Else statement to check if a number is even or odd. The If-Else statement evaluates a condition and executes different code blocks based on whether the condition is true or false. In this case, John can use the modulus operator (%) to check if the number divided by 2 leaves a remainder of 0 (even) or not (odd).

In C++, the "*" (multiplication) operator has higher precedence than the "&&" (logical AND) operator. This means that when evaluating expressions, the multiplication operator will be evaluated before the logical AND operator. Understanding operator precedence is crucial for writing correct and efficient C++ code.

For a function to accept a variable number of arguments, it should use the keyword "varargs" (short for variable-length argument list). Varargs is used in C and some C++ code to create functions that can accept a variable number of arguments. This is often used in functions like printf(), scanf(), and other cases where the number of arguments can vary.

In C#, if overloaded functions have default arguments that could lead to ambiguity in function calls, it's important to avoid such situations. Ambiguity arises when the compiler cannot determine which overloaded function to call because the arguments provided match multiple overloaded versions.

David should implement the "Switch" statement for his calculator program. It's designed for scenarios where multiple options need to be considered based on a single variable's value (in this case, the user's input).

Using too many inline functions can lead to memory bloat. When functions are inlined, their code is duplicated wherever they are called. This can lead to an increase in the size of the compiled code and, consequently, higher memory consumption.

The term for the actual body of a function where detailed processing statements are written is "Implementation." It's in the implementation that you provide the logic and functionality for the function. The other options have different meanings: Prototype is a declaration of the function, Definition is a broader term encompassing various aspects of a function, and Signature refers to the function's name and parameter list.